Yellow Lines in Singapore

Have you all realised that there are more and more yellow lines recently? I guess the most common one that comes to many's mind is the MRT platform yellow line, which comes along with loud, multi-languaged reminders: "For your own safety, please stand behind the yellow line. (and again) Please stand behind the yellow line. Thank you." This is one of the irritating things I hear every weekday mornings. I personally feel that those are redundant.

Do we need yellow lines before our home lifts(maybe on every floors?), as the doors may catch our fingers or close on us? And yellow arrows like those on MRT platforms, so that people entering the lift can give way to those exiting?

Yellow lines are also widely used to mark the X junctions on roads and of course the double yellow lines, which may have once caused you fines with summon tickets issued. These are appropriate and useful as they ensure road safety, even at night. About a month back, I took notice of yellow lines near the edge of walking pavements beside traffic lights. Do pedestrians need yellow lines to tell that standing out of pavement is dangerous and irresponsible?

The last type that I can think of. Yellow lines for smoking area markings. Yellow boxes have been used to indicate designated smoking areas in army camps, as well as in eating places now, in accordance to this month's new smoking ban.

A number of things that might to be marked yellow(in future, or already marked?):
-Designated spots for burning of incense papers during Hungry Ghost Festivals
- Before lifts so that we will not get ourselves hurt from lift doors and also with yellow arrows near the door sides so that we will remember to give way to alighting users
- Designated spots that newstands are allowed to park and extend their displays within
- Areas where we are allowed to pitch tents or place picnic mats in parks
- Queue lines before the ezlink self-help machines so that we can wait orderly for our turn

Have I missed out any?